Deep Vein Thrombosis

First recognised back in 1946, travel related DVT is an added potential problem for 'at risk' travellers who are immobile for extended periods of time. While the problem is often associated with air travel, the risk is equally reported among those travelling by car, coach and train.
What is Travel Related DVT?

A Deep Vein Thrombosis (DVT) is a clotting of the blood in any of the deep veins - usually in the calf. If a clot develops, it usually makes its presence known by an intense pain in the affected calf. Medical attention should be sought immediately if this occurs, especially after a long journey. In some cases this can be fatal, if the clot breaks off and makes its way to the lungs where it can then affect the lung's ability to take in oxygen.

A DVT can occur some days or even weeks after a trip.
Most cases have at least 3 predisposing risk factors - the risk increases as risk factors increase.
Who is at risk?
Very little established research exists in relation to travel. However we do have a wealth of information from hospital research specific to DVT. We already know that the following factors increase the risk of travel related DVT:

Immobility for an extended period of time
An existing history of DVT
Malignancy
Recent surgery or leg surgery
Existing clotting abnormality
Obesity
Chronic illnesses
Hormones or the oral contraceptive pill
Varicose veins
Pregnancy or 2 months post-partum
History of Cardiac problems
Dehydration

How many people are affected?
It is hard to establish just how many people are affected by DVT after travel related activities, as no official records are kept. However it is important to be aware that it is a potential problem for those with risk factors, due to the evidence we already have.
How can I reduce my risk?
Those in a high-risk category should see their travel health advisor before they travel and discuss prevention.
Those at risk should try to exercise at least every hour on long journeys. Exercise the calf muscles by rotating your ankles, or making use of the commercially available exercise equipment. The risk applies to any form of travel where you are routed to one place for hours at the time.
Good hosiery will encourage circulation. However it is important that you do not wear clothing that will cause a restriction of circulation. Any hosiery should be measured properly to ensure a suitable fit.
For long flights wear loose clothing. Due to the change in atmospheric pressure in a plane, parts of your body can expand due to increased gas! In the dry environment of a plane, it is a well-documented fact that too much alcohol, tea and coffee on flights can add to the problem of dehydration. It is therefore very important to remain hydrated during a long flight by drinking plenty of water and fruit juices.
In-Flight Stockings and Socks

With much attention given over the potential risks associated with Travel Related Deep Vein Thrombosis, it is not surprising that many people are looking for products, which will offer protection. Research has shown that correctly fitting anti-thrombosis stockings increase blood flow, thus lowering the risk of DVT in those at risk. Advice related to stocking/socks should apply to all forms of travel when a passenger is sitting still for a long period of time.
Before buying any products it is essential that you are able to assess your personal risk factors and obtain advice from your own doctor regarding fitness to fly if you are in any doubt. If you are in a very high-risk category you should seek advice from your doctor and consider postponing your travel plans.

There are many different brands on the market at the moment, each expressing their own unique qualities. It is important that any stocking/sock purchased is fitted properly. A stocking that is too tight and worn by a traveller with existing circulation problems can do more harm than good -- cutting into the skin on a long flight and potentially causing ulceration and increased risk of DVT.

Never guess the size stocking or sock you require - ask to be measured properly. A good stocking/sock will come in a variety of sizes allowing for measurement from the knee to the ankle as well as the foot size. If a stocking is too tight around the knee it will prevent essential venous return causing the blood to pool around the knee.
When buying your stockings/socks make sure they are comfortable with your chosen footwear for travelling. Some stockings can be slightly thicker than normal leg covering and can be potentially restrictive with tight foot wear.
Do not think that if you wear tight knee-highs during a flight you will save some money. Any clothing or tight shoes cutting into the skin around will prevent normal blood flow and increase the risk of travel related DVT.

Wear your stockings around the house prior to travel to ensure you have a good, comfortable fitting. On the morning of your travel put them on when you get dressed, especially if you are travelling a distance to the airport. Hurriedly put on stockings in the airport lounge can cause no end of travel related anxiety!
Stockings are just one-way to help prevent travel related DVT - take advice from your doctor as well as preventative advice related to travel.
Related products:
Airogym - inflatable exercise cushion for use on long haul flightsThe "Travel Telegraph" awarded a 5-star rating to the Airogym - a small inflatable cushion that can be easily packed into your hand luggage, which has been shown to improve circulation by up to 500% when used correctly. View product >>
Anti-embolism stockings can be purchased online and come in a variety of sizes and colours View product >>

Note: This information is designed to complement and not replace the relationship that exists with your existing family doctor or travel health professional. Please discuss your travel health requirements with your regular family doctor or practice nurse.